Dentifrice containing functional film flakes

ABSTRACT

A dentifrice composition comprising an orally acceptable vehicle having distributed therein a water hydratable film flakes having a matrix comprised of a water soluble hydroxy alkyl cellulose polymer and a starch, and having entrained therein a constituent selected from therapeutic cosmetic and decorative materials.

This application is a continuation application of U.S. Ser. No.10/331,312 filed Dec. 30, 2002. BACKGROUND OF THE INVENTION

[0001] 1. Field of the Invention

[0002] This invention relates to a dentifrice and more particularly to adentifrice containing rapidly water hydratable film flakes suspended inthe dentifrice composition which impart to the dentifrice decorative,cosmetic and therapeutic benefits.

[0003] 2. The Prior Art

[0004] Aesthetic effects have been acknowledged to play an importantrole in consumer acceptance of many products. In many cases ornamentaleffects have been used to distinguish particular products in themarketplace and identify products having particular distinct properties.In the dentifrice field, substantially clear dentifrice products such astoothpastes and gels which have incorporated therein contrasting coloredflakes are known. Such flakes provide an aesthetic effect which theconsumer finds pleasing and promotes the use of the dentifrice,particularly by children. Although such products have met with consumerapproval, the art seeks to further improve the aesthetic effects as wellas the cosmetic and therapeutic benefits of these products so as toencourage the use of dentifrices in practicing oral hygiene.

SUMMARY OF THE INVENTION

[0005] In accordance with the present invention there is provided adentifrice having suspended therein flakes of a water hydratable film(hereinafter film flakes) comprised of a homogeneous mixture of a watersoluble hydroxyalkyl cellulose polymer and starch, the film matrixhaving entrained therein an agent selected from therapeutic, cosmeticand decorative agents.

[0006] In one embodiment of the invention there is provided anaesthetically decorative dentifrice having distributed throughout filmflakes in which a decorative colorant is entrained in the film matrix,the dentifrice vehicle being substantially clear so that theaesthetically decorative effect can be viewed by the user.

[0007] In a second embodiment, therapeutic agents such as antibacterialagents and fluoride anticaries salts, are entrained in the film flakematrix.

[0008] In a third embodiment cosmetic agents such as sweetening agents,breath freshening agents, are entrained in the film flake matrix whichflavorants are rapidly released as the flakes disintegrate duringtoothbrushing, delivering a pleasing burst of sweetness or breathfreshening flavor into the oral cavity.

[0009] The entrainment of the therapeutic and cosmetic agents in thefilm flake matrix suspended in the dentifrice isolates these agents frominteraction with reactive ingredients present in the dentifrice so thatthe agents are maintained substantially separate from the reactivedentifrice ingredients during manufacture and storage while subsequentlybeing released from the film matrix when the dentifrice containing thefilm flakes is topically applied to the tooth surface as by toothbrushing.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0010] The term “substantially clear” when used in to describe thepresent invention shall mean translucent or transparent. The term“dentifrice” shall include toothpastes and gels.

[0011] The Film Flakes

[0012] The film flakes of the present invention are formed from a matrixcomprised of hydroxyalkyl methylcellulose starch and starch film formingagents in which is entrained a colorant such a dye or pigment, aflavorant, sweetener and/or a therapeutic agent such as an antibacterialagent or a breath freshening agent. The film matrix can further comprisewater, additional film forming agents, plasticizing agents, surfactantsand emulsifying agents.

[0013] Preparation of Film Matrix

[0014] In preparing the film matrix according to the present inventionthe hydroxyalkylmethyl cellulose, a starch ingredient, a colorant,flavor, sweetener and/or therapeutic agents and other film formingingredients are dissolved in a compatible solvent to form a film formingcomposition. The film forming composition is cast on a releasablecarrier and dried to form a sheet of film matrix material. The carriermaterial must have a surface tension which allows the film solution tospread evenly across the intended carrier width without soaking to forma destructive bond between the film carrier substrates. Examples ofsuitable carrier materials include glass, stainless steel, Teflon andpolyethylene-impregnated paper. Drying of the film may be carried out athigh temperature using a drying oven, drying terminal, vacuum drier, orany other suitable drying equipment which does not adversely effect theingredients of which the film is composed.

[0015] The film thickness ranges in size from 0.5 to 10 microns andpreferably 2 to 3 microns. The dried film of the present invention isthen cut or punched into shaped flakes having a particle size of 0.01 to0.50 inches preferably 0.08 to 0.25 inches.

[0016] Additional stability can be provided to the shapes formed fromthe dried film, by applying to the film, before shaping into flakes, aprotective barrier overcoat such as a food grade shellac or ethylcellulose.

[0017] When the film is to be used for decorative effect, the film onceformed is punched into various attractive shaped flakes such as hearts,stars, diamonds and circles. The film flakes are incorporated in thebase dentifrice of the present invention at a concentration of about0.05 to 1.0% by weight and preferably 0.1 to about 0.5% by weight.

[0018] Film Forming Agents

[0019] The major film forming agent used to prepare the film matrix ofthe present invention is an hydroxyalkyl cellulose such as hydroxypropylmethyl cellulose, hydroxyethylpropyl cellulose, hydroxybutyl methylcellulose, hydroxy propyl methyl cellulose and carboxymethyl cellulose.Preferably the cellulose polymer is a low viscosity hydropropylmethylcellulose polymer (HPMC). When HPMC is used as the film forming agent itis preferred that the HPMC have a viscosity in the range of about 1 toabout 40 millipascal seconds (mPa·s) as determined as a 2% by weightaqueous solution of the HPMC at 20° C. using a Ubbelohde tubeviscometer. Preferably the HPMC has a viscosity of about 3 to about 20mPa·s at 20° C.

[0020] HPMC is available commercially from the Dow Chemical Companyunder the trade designation Methocel E5 LV. Methocel E5 LV is a USPgrade, low viscosity HPMC having 29.1% methoxyl groups and 9%hydroxyproxyl group substitution. It is a white or off-whitefree-flowing dry powder. As a 2 wt. % solution in water as measured witha Ubbelohde tube viscometer it has a viscosity of 5.1 mPa·s at 20° C.

[0021] The hydroxyalkyl methyl cellulose is incorporated in the filmmatrix in amounts ranging from about 10 to about 60% by weight andpreferably about 15 to about 40% by weight.

[0022] Cold water swellable, physically modified and pregelatenizedstarches are particularly useful as texture modifier to increase thestiffness of the hydroxyalkyl methyl cellulose film matrix of thepresent invention. In the preparation of such starch products, thegranular starch is cooked in the presence of water and possibly anorganic solvent at a temperature not higher than 10° C. higher than thegelatinization temperature. The obtained starch is then dried.

[0023] Pregelatinized corn starch is available commercially. A preferredstarch is available under the trade designation Cerestar PolarTex-Instant 12640 from the Cerestar Company. This Cerestar starch is apregelaterized, stabilized and crosslinked waxy maize starch. It isreadily dispersible and swellable in cold water. In its dry form, it isa white free flowing powder with an average flake size no greater than180 micrometers and 85% of the flakes are smaller than 75 micrometers.It has a bulk density of 44 lbs/ft³.

[0024] The Cerestar starch has excellent cold storage and freeze-thawstability. It has a rapid hydration rate and can reach extremely highviscosity without cooking. It has a smooth and creamy texture similar tocook-up starches. It also has excellent paste clarity and a blandflavor.

[0025] The pregelatinized starch is present in the film matrix of thepresent invention in an amount ranging from about 5 to about 50% byweight and preferably about 10 to about 35% by weight.

[0026] The hydroxyalkyl cellulose to starch ratio (by weight) may varyfrom about 1:3 to about 4:1 and preferably about 1:1.5 to about 2.5:1.

[0027] Decorative Film Flake Ingredients

[0028] Colorants used to prepare the film flakes as well as thedentifrice into which the film flakes may be suspended, arepharmacologically and physiologically non-toxic when used in thesuggested amounts. The colorants include both pigments and dyes.Pigments useful in the practice of the present invention includenon-toxic, water insoluble inorganic pigments such as titanium dioxide,titanium dioxide coated mica (Timiron), chromium oxide greens,ultramarine blues and pinks and ferric oxides as well as water insolubledye lakes prepared by extending calcium or aluminum salts of FD&C dyeson alumina such as FD&C Green #1 lake, FD&C Blue #2 lake, FD&C R&D #30lake and FD&C # Yellow 15 lake. The pigments have a flake size in therange of 5 to 1000 microns, preferably 250 to 500 microns. Pigments areincorporated in the decorative film matrix of the present invention inan amount ranging from about 1 to about 10% by weight and preferablyabout 2 to about 5% by weight.

[0029] A particularly preferred class of dyes are those available fromMicropowders, Inc. under the trade designation Spectra bead which arehigh molecular weight polyethylene powders permanently colored with dyessuch as FD&C Blue #1 aluminum lake.

[0030] Dyes used in the practice of the present invention aredistributed uniformly throughout the film flake matrix or the dentifriceand are desirably food color additives presently certified under theFood Drug & Cosmetic Act for use in food and ingested drugs, includingdyes such as FD&C Red No. 3 (sodium salt of tetraiodofluorescein), FoodRed 17, disodium salt of6-hydroxy-5-{(2-methoxy-5-methyl-4-sulphophenyl)azo}-2-naphthalenesulfonicacid, Food Yellow 13, sodium salt of a mixture of the mono anddisulphonic acids of quinophtalone or 2-(2-quinolyl) indanedione, FD&CYellow No. 5 (sodium salt of4-p-sulfophenylazo-1-p-sulfophenyl-5-hydroxypyrazole-3 carboxylic acid),FD&C Yellow No. 6 (sodium salt ofp-sulfophenylazo-B-naphtol-6-monosulfonate), FD&C Green No. 3 (disodiumsalt of4-{[4-(N-ethyl-p-sulfobenzylamino)-phenyl]-(4-hydroxy-2-sulfoniumphenyl)-methylene}-[1-(N-ethyl-N-p-sulfobenzyl)-Δ-3,5-cyclohexadienimine],FD&C Blue No. 1 (disodium salt ofdibenzyldiethyl-diaminotriphenylcarbinol trisulfonic acid anhydrite),FD&C Blue No. 2(sodium salt of disulfonic acid of indigotin) andmixtures thereof in various proportions.

[0031] The concentration of the dye is present in the film matrix in anamount ranging from about 0.5 to about 5 and preferably about 1 to about4% by weight.

[0032] The dentifrice base in which the film flakes are suspended ispreferably substantially clear and contains a dye or pigment contrastingto that incorporated in the film flakes. Concentration of a contrastingdye or pigment in the dentifrice can range in an amount from about 0.05percent to about 10 percent by weight with respect to the weight of thebase dentifrice and preferably present from about 0.1 percent to about 5percent by weight of the weight of the dentifrice base.

[0033] The film matrix of the present invention is rupturable duringtooth brushing so that flavors, sweeteners as well as therapeutic agentsmay be maintained substantially separate from the dentifrice ingredientsduring manufacture and storage, while subsequently being released whenthe dentifrice is applied topically to tooth surfaces, the mechanicalagitation created during tooth brushing effecting rupture of the filmmatrix whereby the entrained ingredient is released to the toothsurface.

[0034] Cosmetic Agents

[0035] Flavor agents incorporated in the film matrix of the presentinvention are known to the prior art, such as natural and artificialflavors. These flavorings may be chosen from synthetic flavor oils andflavoring aromatics, and/or oils, oleo resins and extracts derived fromplants, leaves, flowers, fruits and so forth, and combinations thereof.Representative flavor oils include: spearmint oil, cinnamon oil,peppermint oil, clove oil, bay oil, thyme oil, cedar leaf oil, oil ofnutmeg, oil of sage, and oil of bitter almonds. These flavor agents canbe used individually or in admixture. Commonly used flavors includemints such as peppermint, artificial vanilla, cinnamon derivatives, andvarious fruit flavors, whether employed individually or in admixture.Generally, any flavoring or food additive, such as those described inChemicals Used in Food Processing, publication 1274 by the NationalAcademy of Sciences, pages 63-258, may be used. Generally the flavoringagent is incorporated in the film of the present invention in an amountranging from about 1 to about 30% by weight and preferably about 15 toabout 25% by weight.

[0036] Sweeteners may also be incorporated in the film matrices of thepresent invention include both natural and artificial sweeteners.Suitable sweetener include water soluble sweetening agents such asmonosaccharides, disaccharides and plysaccharides such as xylose,ribose, glucose (dextrose), mannose, glatose, fructose (levulose),sucrose (sugar), maltose, water soluble artificial sweeteners such asthe soluble saccharin salts, i.e., sodium or calcium saccharin salts,cyclamate salts dipeptide based sweeteners, such a L-aspartic acidderived sweeteners, such as L-aspartyl-L-phenylalaine methyl ester(aspartame).

[0037] In general, the effective amount of sweetener is utilized toprovide the level of sweetness desired for a particular film matrixcomposition, will vary with the sweetener selected. This amount willnormally be about 0.01% to about 2% by weight of the composition.

[0038] Therapeutic Agents

[0039] Therapeutic agents incorporated in the film flake matrix of thepresent invention are compounds that are reactive with dentifriceingredients and must therefore be isolated from the dentifriceingredients during manufacture and storage.

[0040] The therapeutic agents entrained in the film matrix maintainedsubstantially separate from the ingredients of the base dentifriceduring manufacture and storage are subsequently released into thedentifrice during tooth brushing. Entrainment of the therapeutic agentin the film matrix prevents premature leakage into the dentifrice sothat in the case of therapeutic agents which are reactive ingredients,interaction with dentifrice ingredients is avoided.

[0041] For example, reaction of a cationic therapeutic agent such ascetyl pyridinium chloride or chlorhexidene with an anionic surfactantsuch as sodium lauryl sulfate, which surfactant is conventionallyincluded in dentifrice compositions, inactivates the therapeutic agentthereby reducing the antibacterial efficacy of the dentifricecomposition.

[0042] In the use of fluoride salts as anticavities agents, one of themethods used to achieve enhanced fluoridation known to the art (U.S.Pat. No. 5,045,305 and U.S. Pat. No. 5,145,668), is to mix, immediatelybefore use, separate solutions containing fluoride and calcium salts.Such a procedure is a time consuming daily chore which discourages itsuse. Combining the calcium and fluoride salts into a single dentifricecomposition will not provide an effective means for fluoridation as thepresence of the calcium salt reacts with and removes bioactive solubleionic fluoride from the dentifrice by forming insoluble and inactivecalcium fluoride thereby reducing the antiocariogenic effectiveness ofthe fluoride dentifrice. Incorporating the calcium salt in the flakesformed from the film matrix of the present invention isolates thefluoride ion in the dentifrice from interaction with the calcium saltuntil the film matrix disintegrates during tooth brushing.

[0043] Typically, in the case of calcium salts, these salts are presentin the film flake matrix in an amount up to about 30% by weight, basedon the weight of the film matrix, and preferably in the amount of about18% to 22%.

[0044] In addition to fluoride or calcium salts, there may also beincluded in the film flake matrix anticalculus agents such aspyrophosphate salts including dialkali or tetraalkali metalpyrophosphate salts such as Na₄P₂0₇, K₄P₂0₇, Na₂K₂P₂0_(7,) Na₂H₂P₂0₇ andK₂H₂P₂0₇, long chain polyphosphates such as sodium hexametaphosphate andcyclic phosphates such as sodium trimetaphosphate which are included inthe film matrix at a concentration of about 15 to 20% by weight.

[0045] Other active agents which may be incorporated it he film matrixof this invention include antibacterial agents such as Triclosan, breathfreshening agents such as zinc gluconate, zinc citrate and/or alphaionone, desensitizers such as potassium nitrate, vitamins such aspantheon, retinyl palmitate, tocopherol acetate, herbs such aschamomilla recutita, mentha piperita, salvia officinalis, commiphoramyrrha, whitening agents such as hydrogen peroxide and urea peroxide,high cleaning silica, preservatives, silicones, chlorophyll compounds.

[0046] The active agents are incorporated in the film matrix of thepresent invention at a concentration of about 0.1 to about 2.0% byweight and preferably about 0.15 to about 5% by weight. The presentinvention is illustrated by the following examples.

[0047] Base Dentifrice Composition

[0048] In the preparation of the base dentifrice in accordance with thepresent invention there is utilized an orally acceptable vehicle,including a water-phase with humectant which is preferably glycerine orsorbitol or an alkylene glycol such as polyethylene glycol or propyleneglycol, wherein the water is present typically in amount of about 5 toabout 10% by weight and the glycerine, sorbitol and/or the alkyleneglycol ingredients typically total about 30 to about 80% by weight ofthe dentifrice, more typically about 50 to about 70% by weight.

[0049] The base dentifrice also contains an inorganic or a natural orsynthetic thickener or gelling agent in proportions of about 0.10 toabout 5% by weight, preferably about 0.2 to about 1% by weight. Theseproportions of thickeners in the dentifrice compositions of the presentinvention in which the film flakes of the present invention aresuspended are sufficient to form an extrudable, shape-retaining productwhich can be squeezed from a tube onto a toothbrush and will not fallbetween the bristles of the brush but rather, will substantiallymaintain its shape thereon. Suitable thickeners or gelling agents usefulin the practice of the present invention include inorganic thickeningsilicas such as amorphous silicas available from Huber Corporation underthe trade designation Zeodent 165, Irish moss, iota-carrageenan, gumtragacanth, and polyvinylpyrrolidone.

[0050] Polishing agents such as silica, calcined alumina, sodiumbicarbonate, calcium carbonate, dicalcium phosphate and calciumpyrophosphate may be included in the base dentifrice compositions usedin the practice of the present invention. Visually clear dentifricecompositions are obtained by using polishing agents such as collodialsilica, such as those sold under the trade designation Zeodent 115available from the Huber Corporation or alkali metal aluminosilicatecomplexes (that is, silica containing alumina combined in its matrix)which have refractive indices close to the refractive indices of gellingagent-liquid (including water and/or humectant) systems used indentifrice compositions.

[0051] The polishing agent is generally present in the base dentifricecomposition in weight concentrations of about 3% to about 50% by weight.

[0052] Surfactants are used in the base dentifrice compositions of thepresent invention to achieve increased prophylactic action and renderthe instant compositions more cosmetically acceptable. Suitable examplesof surfactants include water-soluble salts of higher fatty acidmonoglyceride monosulfates, such as the sodium salt of the monsulfatedmonoglyceride of hydrogenated coconut oil fatty acids, cocamidopropylbetaine, higher alkyl sulfates such as sodium lauryl sulfate, alkyl arylsulfonates such as sodium dodecyl benzene sulfonate, higher alkylsulfoacetates, sodium lauryl sulfoacetate, higher fatty acid esters of1,2-dihydroxy propane sulfonate, and the substantially saturated higheraliphatic acyl amides of lower aliphatic amino carboxylic acidcompounds, such as those having 12 to 16 carbons in the fatty acid,alkyl or acyl radicals, and the like. Examples of the last mentionedamides are N-lauroyl sarcosine, and the sodium, potassium, andethanolamine salts of N-lauroyl, N-myristoyl, or N-palmitoyl sarcosine.

[0053] The anionic surfactants are typically present in the dentifricecompositions of the present invention in an amount of about 0.3to about5% by weight, preferably about 0.5 to about 2.0% by weight.

[0054] To prepare the dentifrice base of the present invention, water,humectants, e.g. glycerin, sorbitol polyethylene glycol are dispersed ina conventional mixer until the mixture becomes a homogeneous gel phase.Into the gel phase are added the polishing agent. These ingredients aremixed until a homogeneous phase is obtained. Thereafter the thickener,any flavor and surfactant ingredients are added and the ingredientsmixed at high speed until vacuum of about 20 to 100 mmHg. The shapedfilm flakes are added to the dentifrice constituents as a last step, soas to minimize the shear to which the dentifrice ingredients aresubjected to during the prior mixing steps.

EXAMPLE I

[0055] Silver colored film flakes were prepared by using the ingredientslisted in Table I below. In preparing the film, the HMPC polymerMethocel E5LV having a viscosity of 5.1 mPa·s (2% aqueous solution) wasadded to deionized water at 23° C., and the solution stirred for 5minutes. To this solution was added the pregelatized starch CerestarPolar Tex Instant 12640 and stirred vigorously for about one hour untilthe starch was completely dispersed and a homogeneous mixture wasformed. To this mixture was added the titanium coated mica and mixed for10 minutes after which the sodium lauryl sulfate surfactant was addedand mixed for an additional 15 minutes. Thereafter spearmint flavor wasthoroughly mixed for an additional 40 minutes to form a slurry emulsion.The weight ratio of HPMC to Starch was 2:1. The emulsion was then caston a polyethylene coated paper at 25° C. and dried at 110° C. to form asolid thin film having a thickness of 2.5 microns. Star shaped flakespunched from the dried film had a particle size of 0.25 inches.

[0056] A transparent green colored base dentifrice composition havingthe ingredients listed in Table II was prepared, wherein a vehiclesolution of the sorbitol and water was made and subjected to 28-30 lbs.applied vacuum and a mixture of saccharin sodium fluoride and was addedthereto. Subsequently, a green dye was blended with the vehicle. Themixture was degassed at 28-30 lbs. applied vacuum over a 5 minuteperiod. Then Zeodent 115 silica abrasive and Zeodent 165, an amorphoussilica thickening agent and sodium lauryl sulfate (SLS) were added afterpreliminary degassing. The ingredients were mixed. After about 5 minutesmixing, with application of vacuum, the dentifrice preparation wasconsidered to be complete and thereafter 0.3% by weight of the starshaped film flakes were suspended in the dentifrice.

[0057] After packaging, the dentifrice product was squeezed from a tubeand was extruded as a distinctive green, aesthetically pleasing ribbonproduct having suspended therein clearly visible star shaped silvercolored flakes extending throughout the extruded product. TABLE I SILVERFILM MATRIX Ingredients Wt. % Starch 21.0 HPMC 40.0 Glycerin 5.0Vegetable oil 3.0 Tween 80 1.0 SLS 1.0 Sodium saccharin 0.3 Titaniumcoated mica 3.8 Flavor 24.6 Zinc gluconate 0.3 Total 100

[0058] TABLE II GREEN BASE DENTIFRICE Ingredients Wt. % PEG 600 3.0Sodium carboxymethyl cellulose 0.55 Sorbitol 74.0 Purified water 6.357Sodium fluoride 0.243 Tetrasodium pyrophosphate 0.50 Sodium saccharine0.30 Zeodent 115 4.0 Zeodent 165 8.8 Sodium lauryl sulfate 1.2 Flavor1.0 FD&C Green (2% soln.) 0.05 Total 100

EXAMPLE II

[0059] A second film flake was prepared following the procedure ofExample I. The ingredients of the film matrix are listed in Table IIIbelow. TABLE III RED FILM Ingredients Wt. % HPMC 48.0 Cornstarch 12.0Propylene glycol 2.0 Tween 80 2.0 Vegetable oil 4.0 Flavor 24.0 FD&C #334.0 Titanium oxide coated mica 4.0 Total 100

[0060] The thickness of the film was 3.0 microns. Thereafter 0.2% byweight of heart shaped flakes having a particle size of 0.125 incheswere die cut from the film. Shellac (100% non-bleached) was applied tothe film before the heart shapes were die cut from the matrix. The heartshaped flakes were then incorporated into the dentifrice base of TableII as the last step, so as to minimize the shear to which they aresubjected to during mixing.

[0061] After packaging, the dentifrice product was squeezed from a tubeand was extruded as a distinctive blue, aesthetically pleasing producthaving suspended therein clearly visible heart shaped red colored flakesextending randomly throughout the extruded product.

Example III

[0062] Film flakes suitable for the delivery of a flavor burst having ahigh flavor concentration (23.75wt. %) was prepared following theprocedure of Example I, the ingredients of which are listed in Table IV.Flakes in the shape of circles formed from the film were suspended in abase dentifrice of type disclosed in Table II. When brushed on teeth thedentifrice emitted a burst of flavor as the brushing caused themechanical rupture of the film with the immediate release of its flavorconstituent. TABLE IV Ingredients Wt. % HPMC 48.0 Cornstarch 12.0 Tween80 2.0 Propylene glycol 2.0 Canola oil 4.0 Flavor 23.75 Titanium coatedmica 8.0 Sodium fluoride 0.243 Total 100

EXAMPLE IV

[0063] A film of 2.5 microns thickness containing a high concentrationof calcium acetate (21.4% by weight) was prepared following theprocedure of Example I having the ingredients listed in Table V below:TABLE V Ingredients Wt. % HPMC 43.0 Calcium acetate 21.4 Tween 80 1.8Propylene glycol 1.8 Canola oil 3.5 Flavor 21.4 Titanium coated mica 7.1Total 100

[0064] 0.3% by weight film flakes of 0.25 inch particle size of Table Vwere suspended in a commercial fluoride toothpaste containing 1100 partsper million (ppm) fluoride ion. The toothpaste containing the filmflakes designated “Paste A”, was then aged at 120° F. for 2 to 8 weeksand analyzed for fluoride content at weekly intervals. For purposes ofcomparison, the same toothpaste to which the film flakes had not beenincorporated designated “Paste B”, was also analyzed for fluoride levelsduring the same two week interval.

[0065] The presence of fluoride ion in the dentifrice at each weekinterval was determined by separating the base from the flakes firstthen analyzing the base for the presence of fluoride using F⁻ ionselective electrodes. The results of these assays are recorded in TableVI below.

[0066] The fluoride assays of the two toothpastes are recorded in TableVI below. TABLE VI Weeks 1 2 3 4 8 Paste (ppmF-) (ppmF-) (ppmF-) (ppmF-)(ppmF-) A 935 962 900 943 899 B 1016 1042 986 1036 1040

[0067] The results recorded in Table VI show a minimal loss of fluorideion over the 8 week assay period in Paste A containing film entrainedcalcium acetate as compared to Paste B which did not contain any calciumsalt. When brushed on teeth of the film suspended in the dentifrice willrapidly disintegrate whereby calcium ion will be released to interactwith the fluoride ion to enhance the anticaries efficacy of the fluorideion on the teeth being brushed.

EXAMPLE VI

[0068] Cetyl pyridinium chloride (CPC) is incompatible with sodiumlauryl sulfate (SLS) a surfactant widely used in dentifricecompositions. Because of this incompatibility CPC has not foundapplication in most dentifrice formulations. In Table VII below there islisted the ingredients of a film matrix in which CPC is entrained. Thefilm when suspended in a SLS containing dentifrice will not react withthe SLS present in the dentifrice. The CPC will be released during toothbrushing without being inactivated by the presence of SLS in thetoothpaste base. TABLE VII Ingredients Wt. % HPMC 48.0 CPC 12.0 Tween 802.0 Propylene glycol 2.0 Canola oil 4.0 Flavor 24.0 Titanium coated mica8.0 Total 100

What is claimed is:
 1. A dentifrice composition comprising an orallyacceptable vehicle having distributed therein flakes formed from a waterhydratable film matrix, the matrix being comprised of a homogeneousmixture of a water soluble hydroxyalkyl cellulose polymer and a starch,and having entrained therein a constituent which functions to providedecorative, cosmetic and therapeutic effects.
 2. A dentifrice accordingto claim 1 wherein the film flake matrix has entrained therein adecorative constituent.
 3. A dentifrice according to claim 2 whereinfilm flake has an aesthetically pleasing shape.
 4. A dentifriceaccording to claim 1 wherein the film flake matrix has entrained thereina cosmetic constituent.
 5. A dentifrice according to claim 1 wherein thefilm flake matrix has entrained therein a therapeutic constituent.
 6. Adentifrice according to claim 1 in which the dentifrice is asubstantially clear gel and the film flake matrix contains a decorativecolorant which is visible therein.
 7. The dentifrice according to claim1 in which the film flake matrix comprises from about 0.05 to about 1.0%by weight of the dentifrice.
 8. The dentifrice of claim 1 wherein adecorative constituent entrained in the film flake matrix is a colorant.9. The dentifrice of claim 1 wherein the therapeutic constituententrained in the film flake matrix is an antibacterial agent.
 10. Thedentifrice of claim 1 wherein the therapeutic constituent entrained inthe film flake matrix is a calcium or fluoride salt.
 11. The dentifriceof claim 1 wherein the cosmetic constituent entrained in the film flakematrix is a flavorant.
 12. The dentifrice of claim 11 wherein theflavorant is present in the film flake matrix at a concentration ofabout 15 to about 25% by weight.
 13. The dentifrice of claim 1 whereinthe film flake matrix is a shaped two dimensional flake.